1. Field of the Invention
The invention relates generally to voltage regulators. More specifically, the invention relates to a compact voltage regulator which can be used with wireless communications devices.
2. Description of the Related Art
Modern wireless communications devices, such as Code Division Multiple Access (CDMA) telephones and other cellular telephones are held to ever-higher performance standards. Ongoing research work is being performed for communication devices to provide clear and undistorted transmission. To achieve this, linear power amplifiers are used in wireless communication devices. The linear power amplifiers require constant quiescent current through operating conditions to maintain linearity. To provide the constant quiescent current, a regulated voltage is needed.
Usually, a voltage regulator is implemented on a separate die and the regulated voltage is provided to the linear power amplifiers. In mobile phones, the voltage regulator may be a stand alone or integrated with other circuits. The requirement of an additional die increases the manufacturing cost. Therefore, to minimize the cost, there is a need for a compact voltage regulator which may be implemented on the same die as the linear power amplifier.